What is Internet Protocol (IP)? The Internet Protocol is a set of rules for addressing and routing packets across interconnected networks. These rules help deliver packets toward their intended destinations.
Data sent over the internet is divided into smaller sections called packets. Each packet includes addressing information that routers use to forward it toward the correct network.
Components of the Internet Protocol Datagram
- IP Identification (IPID) Used to uniquely identify IP datagrams and for reassembly of fragmented packets.
- Time-to-live (TTL) Attempts to keep datagrams and packets from routing in circles. When TTL reaches 0, the datagram is dropped. The TTL allows traceroute to function, identifying each router in a network by sending out datagrams with successively increasing TTLs, and tracking when those TTLs are exceeded.
- Protocol Describes the higher-level protocol embedded within the datagram.
- Source IP Address The IP address of the host where the datagram was created.
- Destination IP Address The destination where the datagram should be sent.
How Does Internet Protocol Work?
The following analogy provides a simplified way to understand how the Internet Protocol fits into the broader networking model.
Imagine you are relocating your family to a new city.
- Data: The contents of the boxes represent application data.
- Link layer: The roads represent the local network connection.
- Network layer: The moving truck represents IP, which carries packets between networks.
- Transport layer: The boxes represent TCP or UDP segments and datagrams.
- Application layer: The contents of the boxes represent application protocols such as HTTP, FTP, or SSH.
- IP address: The address of the destination house represents the IP address.
- Port number: The rooms in the house represent ports that identify specific services.
What Is an IP Packet?
In computer networks jargon, an IP packet is a container or package that carries data over a TCP/IP network. This type of packages is often carried as the payload inside an Ethernet frame. A frame that contains the packages source and destination MAC addresses in the header.
An IP header is composed of a series of pieces of information about the packet. Above all, his information contains the senders and receiver IP address. This information includes;
- Header length
- Length of the packet
- The number of networks hops
- Protocol type (TCP, UDP, etc.)
What is the Transmission Control Protocol or TCP/IP?
The TCP/IP networking model defines the process for a computer network to work. This networking model breaks the functions into a small number of categories called layers. Most importantly, the most popular TCP/IP application today is the web browser.
TCP is similar to sending someone a message written on Lego blocks through the mail. Each piece can travel by a different route and arrive out of order; TCP reassembles the data and manages retransmission when needed.
User Datagram Protocol or UDP
Most importantly, UDP is a communications protocol that facilitates the exchange of messages between computing devices in a network. It’s an alternative to the transmission control protocol (TCP). In a network that uses the Internet Protocol (IP), it is sometimes referred to as UDP/IP.
UDP divides messages into datagrams. Routers forward IP packets, while switches forward data-link frames. UDP includes source and destination port numbers so applications can be identified. Its checksum can help detect corruption, but UDP does not provide delivery, ordering, or retransmission guarantees.
How does IP routing work?
The Internet is made up of interconnected networks responsible for certain blocks of IP addresses. These types of networks are commonly known as autonomous systems or AS.
The routers keep track of all devices in a network. This is done by saving the device information in a routing table. Consequently, this information allows routers to forwards data packets between networks. In other words, packets travel from router to router until one claims responsibility for the targeted location.